Anatomical Study On The Postnatal Development Of The Gastrointestinal Tract In Male Rabbits
Anatomical Study On The Postnatal Development Of The Gastrointestinal Tract In Male Rabbits
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Date
2015-04-08
Authors
Mohammed, Tahany
Journal Title
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Publisher
University of Khartoum
Abstract
1. A gross anatomical, histological and ultrastrctural study has been
conducted on the GIT in 50 male rabbits (Lepus Cunculus) of
different ages. The ages varied between 0-day 30 days.
2. The advancing age is a major factor in the increase of the body
weight, crown rump length, fore limb length and GIT weight, length
and volume, but there was a decrease in some of these parameters at
the age of 30 days. This decrease may be due to the effect of weaning.
3. The location of the stomach in all age groups is similar to that of the
adult.
4. The histology (in 32 animals) and ultrastrcture (in18 animals) of the
mucosa of the fundic region, proximal and distal small intestines, and
caecum and colon were investagated in rabbits of different ages.
5. The histological measurements of the thickness of the fundic mucosa
and length of the pits and length and width of the villi of the proximal
and distal small intestines were studied in 18 rabbits of different ages.
6. The mucopolysaccharide and glycogen were examined in the fundic
region of the stomach, proximal and distal small intestine and colon in
rabbits of different age.
7. The mucosa of the fundic region has different shapes in the different
age groups, specially in the length of the folds and the depth of the
pits.
8. In the fundic region of the stomach, the histology of the surface
epithelial cells and parietal cells and chief cells of the gastric glands
were studied. The muscularis mucosa was arranged into inner circular
layer at 0-day of age, but an additional outer longitudinal layer
appeared in older age groups.
9. The age also has an effect on the shape and length of the intestinal
villi of the small intestine and the crypts of the large intestine. The
mucosa of the small intestine showed simple striated columnar
epithelial cells and prominent goblet cells. The crypts opened adjacent
to the bases of the villi as simple, branched, tubular invaginations.
10. In the stomach fundic region, the epithelial cells contained apical
microvilli, smooth and rough endoplasmic reticulum, free ribosomes,
elongated nucleus, secretary granules, mitochondria and electron
dense material. Cells with round secretary granules of different size
concentrated beneath and lateral to the nucleus were observed in all
age groups may be endocrine cells.
11. The mucosa of the small intestine was covered by columnar cells that
contained apical microvilli, oval nucleus, dilated cisternae of rough
endoplasmic reticulum, Golgi apparatus, vacuoles and material with
electron density in all age groups.
12. In the small intestine, the crypts showed epithelial cells with dilated
intercellular spaces and contained apical microvilli, mitochondria,
material with electron density, rough endoplasmic reticulum and
elongated nucleus. There are cells containing spherical secretary
granules different in size above the nucleus and cells of polymorphic
secretary granules of different sizes beneath and lateral to the nucleus
were observed.
13. The mucosa of the large intestine was composed of crypts with villar
shape at 0-day of age and the length of the crypts decreased with
advancing age. The crypts were lined by striated epithelial cells.
Goblet cells were prominent.
14.The absorptive columnar cells had apical microvilli and contained
vacoules of different size, ovoid to elongated nucleus, mitochondria,
rough endoplasmic reticulum and lateral membranous interdigitations.
Cells with polymorphic secretary granules were noticed.
15. Varing degrees of positive reaction to PAS diastase resistant material
and diastase-digested material was clearly seen in the stomach fundic
region, proximal, and distal small intestine and colon in rabbits of
different ages.
Description
156 Pages
Keywords
Anatomical Study ; Postnatal Development ;Gastrointestinal Tract; Male Rabbits;Light Microscopy;Histochemistry;Gross Anatomy;Histometrical measurments;